Protein kinase G Ialpha disulfide oxidation and the pathogenesis of sepsis
Lead Research Organisation:
King's College London
Department Name: Cardiovascular
Abstract
Sepsis, often referred to as blood poisoning, occurs when bacteria get into the blood stream. This is a very common disease and when it occurs the chances of survival are rather poor. Major issues in sepsis are that the patient blood pressure becomes very low and their blood vessels become leaky. Together this causes a lot of harm and many of the bodies organs are not supplied with enough blood and so they become injured. Recently we identified a new pathway that lowers blood pressure in healthy people. We have some preliminary evidence this mechanism becomes overactive in sepsis to uncontrollably and overly lower blood pressure. We will test if this is true and try and identify strategies that prevent this from happening as these may be protective to humans with sepsis.
Technical Summary
Sepsis is a common and often deadly medical condition that exerts an enormous burden on healthcare systems. Previously we showed that PKGIalpha can be activated by oxidative stress independently of the classical NO-cGMP activation pathway. This alternate activation pathway involves oxidants inducing a disulfide bond between the kinases two subunits. This is potentially relevant to sepsis as it is a time of oxidative stress that may drive formation of the disulfide and this would explain the associated hypotension that causes injury. Consistent with these ideas we have found PKG disulfide formation occurs in mice following LPS treatment, which strongly supports overall hypothesis. Recently we generated 'redox dead' Cys42Ser PKG knock-in mice that cannot be activated by disulfide oxidation. We propose to compare the response of these mice to their wild-type littermate controls during sepsis. We predict that the knock-in will be protected from sepsis-induced hypotension, as will cardiac, lung and kidney function. Indeed our pilot studies have already shown that the knock-in mice are protected in part from LPS-induced hypotension.
Planned Impact
Sepsis is a common and often deadly medical condition that exerts an enormous burden on healthcare systems and society. Current therapeutic strategies of administering antibiotics (to combat the underlying infection) or vasopressor (to elevate blood pressure) are often ineffective, with a high risk (approximately 25%) of mortality. In recent years much attention has been paid to the idea that injury during sepsis is driven by over-production of nitric oxide to detrimentally lower blood pressure by activating soluble Guanylate Cyclase and then protein kinase G (PKG). However, clinical trials preventing nitric oxide production during sepsis were ineffective and in fact increased mortality. Clearly our current understanding of the disease is lacking. By better understanding the mechanisms that underlie the dysfunction that occurs in sepsis we improve our chances of implementing or designing rational therapeutic strategies. Our previous work identified an important new way of activating PKG independently of the nitric oxide pathway, involving it becoming oxidised to form an interprotein disulfide. Sepsis is well-known as a time of oxidative stress and so PKG oxidation may be expected to occur. PKG oxidative activation would logically explain the hypotension that occurs during sepsis. Indeed, we found sepsis induces PKG oxidation and this was associated with murine hypotension in vivo. In contrast a Cys42Ser PKG knock-in mouse that cannot be activated by disulfide oxidation was resistant in part to sepsis-induced hypotension. This knock-in model will be invaluable in determining the importance of PKG oxidation in injury during sepsis, as well as helping us understand this at the molecular level. Indeed, by comparing the knock-in responses to their wild-type littermate controls during sepsis, we may be able to identify protective pharmacological treatment that operate by preventing oxidation-induced over-activation of PKG. Overall we have identified a potentially important new mechanism that may be injurious during sepsis, and we propose studies that may lead to therapies that help treat this major healthcare problem.
Organisations
People |
ORCID iD |
Philip Eaton (Principal Investigator) |
Publications
Wolhuter K
(2018)
Evidence against Stable Protein S-Nitrosylation as a Widespread Mechanism of Post-translational Regulation
in Molecular Cell
Wolhuter K
(2017)
How widespread is stable protein S-nitrosylation as an end-effector of protein regulation?
in Free radical biology & medicine
Valek L
(2017)
Redox-guided axonal regrowth requires cyclic GMP dependent protein kinase 1: Implication for neuropathic pain.
in Redox biology
Stubbert D
(2014)
Protein kinase G Ia oxidation paradoxically underlies blood pressure lowering by the reductant hydrogen sulfide.
in Hypertension (Dallas, Tex. : 1979)
Stathopoulou K
(2016)
S-glutathiolation impairs phosphoregulation and function of cardiac myosin-binding protein C in human heart failure.
in FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Stanley CP
(2019)
Singlet molecular oxygen regulates vascular tone and blood pressure in inflammation.
in Nature
Rudyk O
(2013)
Protein kinase G oxidation is a major cause of injury during sepsis.
in Proceedings of the National Academy of Sciences of the United States of America
Rudyk O
(2017)
Examining a role for PKG Ia oxidation in the pathogenesis of cardiovascular dysfunction during diet-induced obesity.
in Free radical biology & medicine
Rudyk O
(2014)
Biochemical methods for monitoring protein thiol redox states in biological systems.
in Redox biology
Prysyazhna O
(2019)
Blood Pressure-Lowering by the Antioxidant Resveratrol Is Counterintuitively Mediated by Oxidation of cGMP-Dependent Protein Kinase.
in Circulation
Description | An investigation of the potential therapeutic effects of Sulforadex in Noonan syndrome |
Amount | £290,749 (GBP) |
Funding ID | PG/17/44/33064 |
Organisation | British Heart Foundation (BHF) |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 09/2017 |
End | 08/2021 |
Description | Disulfide activated protein kinase G Ialpha as a new therapeutic target in sepsis |
Amount | £502,927 (GBP) |
Funding ID | MR/L009684/1 |
Organisation | Medical Research Council (MRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2014 |
End | 02/2018 |
Description | Does redox state of PKG1alpha control hypoxic vasoconstriction and remodelling in the pulmonary vasculature? |
Amount | £381,870 (GBP) |
Funding ID | FS/14/57/31138 |
Organisation | British Heart Foundation (BHF) |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 04/2015 |
End | 03/2019 |
Description | Does redox state of PKG1alpha control hypoxic vasoconstriction and remodelling in the pulmonary vasculature? |
Amount | £381,870 (GBP) |
Funding ID | FS/14/57/31138 |
Organisation | British Heart Foundation (BHF) |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 04/2015 |
End | 03/2019 |
Description | Does redox state of PKG1alpha control hypoxic vasoconstriction and remodelling in the pulmonary vasculature? |
Amount | £381,870 (GBP) |
Funding ID | FS/14/57/31138 |
Organisation | British Heart Foundation (BHF) |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 04/2015 |
End | 03/2019 |
Description | ERC Advanced - CARDIOREDOX |
Amount | € 2,255,659 (EUR) |
Funding ID | 339095 |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 12/2013 |
End | 11/2018 |
Description | Expanding our understanding of the redox regulation of soluble Epoxide Hydrolase in cardiovascular health and disease |
Amount | £253,143 (GBP) |
Funding ID | PG/15/26/31373 |
Organisation | British Heart Foundation (BHF) |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 04/2015 |
End | 03/2018 |
Description | Furthering our understanding of PKGIα in cardiovascular health and disease |
Amount | £999,700 (GBP) |
Funding ID | RG/17/16/33294 |
Organisation | British Heart Foundation (BHF) |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 03/2018 |
End | 02/2023 |
Description | MRC project grant |
Amount | £502,927 (GBP) |
Funding ID | MR/L009684/1 |
Organisation | Medical Research Council (MRC) |
Sector | Public |
Country | United Kingdom |
Start | 02/2014 |
End | 01/2018 |
Description | Thiol-disulfide redox switches in protein kinases and their role in cardiovascular health and disease |
Amount | £1,462,773 (GBP) |
Funding ID | MR/R01065X/1 |
Organisation | Medical Research Council (MRC) |
Sector | Public |
Country | United Kingdom |
Start | 05/2018 |
End | 04/2019 |
Description | project grant |
Amount | £289,772 (GBP) |
Funding ID | MGU0581 |
Organisation | Queen Mary University of London |
Sector | Academic/University |
Country | United Kingdom |
Start | 06/2021 |
End | 05/2024 |
Title | PEG-switch |
Description | Allso reversible proetin oxidation in candidate proteins to be monitored |
Type Of Material | Technology assay or reagent |
Year Produced | 2013 |
Provided To Others? | Yes |
Impact | People can more easily and routeinely monitor protein thiol redox state |
Title | anti-sulforaphane protein adduct antibody |
Description | Allows sulforaphane-modified proteins to be monitored and identified. |
Type Of Material | Antibody |
Year Produced | 2013 |
Provided To Others? | Yes |
Impact | Has allowed novel targets of sulforaphane to be identified. |
Description | Media interest |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | After we published a paper titled: Protection from hypertension in mice by the Mediterranean diet is mediated by nitro fatty acid inhibition of soluble epoxide hydrolase, we had a lot of press interest and phonecalls with jouralsits froma round the work. Here are a very few examples of the news agencies that cited the work. http://www.dailymail.co.uk/health/article-2632932/Tossing-lettuce-olive-oil-sprinkling-nuts-avocado-boosts-heart-health.html http://www.bbc.co.uk/news/health-27470115 http://www.express.co.uk/news/health/476945/Why-a-Mediterranean-diet-is-good-for-your-health http://www.telegraph.co.uk/health/healthnews/10840283/Olive-oil-on-salad-may-save-your-life.html http://www.independent.co.uk/life-style/health-and-families/health-news/why-is-a-mediterranean-diet-so-good-for-you-scientists-think-they-know-9400889.html Apart from substantive interest from all types of news agencies, we even had members of the public get in contact to discuss the findings. |
Year(s) Of Engagement Activity | 2014 |
URL | http://www.bbc.co.uk/news/health-27470115 |